EX-99.1 2 d13247dex991.htm EX-99.1 EX-99.1 Exhibit 99.1 PRESS RELEASE Prothena’s Partner Roche to Advance Prasinezumab into Phase III Development for Early-Stage Parkinson’s Disease Data from Phase IIb PADOVA study and longer term follow-up data suggest clinical benefit on top of symptomatic treatment in early-stage Parkinson’s disease Prasinezumab is a potential first-in-class anti-alpha-synuclein antibody, targeting a known biological driver of Parkinson’s disease progression Parkinson’s disease affects over 10 million people globally and significant unmet need remains DUBLIN, Ireland, June 15, 2025 - Prothena Corporation plc (NASDAQ:PRTA), today announced partner Roche will advance prasinezumab, an investigational anti-alpha-synuclein antibody, into Phase III development in early-stage Parkinson’s disease. This decision is informed by data from the Phase IIb PADOVA study and ongoing open-label (OLE) extensions from both PADOVA and the Phase II PASADENA study. “As pioneers in developing the first anti-alpha synuclein targeting antibody, we are excited to see Roche advancing prasinezumab into Phase III development, with the potential to deliver the first diseas…
Open exhibit ↗Current Report · Items 8.01, 9.01 · 8-K
PROTHENA CORP PUBLIC LTD CO
PRTANASDAQEQUITYCurrent
Other Events
Item 8.01 Other Events. On June 15, 2025, Prothena Corporation plc (the “Company”) issued a press release announcing that the Company’s partner Roche announced its decision to advance prasinezumab into Phase III development for early-stage Parkinson’s disease. A copy of that press release is attached as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.
Company context
Prothena Corporation plc is a late-stage clinical biotechnology company with expertise in protein dysregulation and a pipeline of investigational therapeutics with the potential to change the course of devastating neurodegenerative and rare peripheral amyloid diseases. Fueled by its deep scientific expertise built over decades of research, Prothena is advancing a pipeline of therapeutic candidates for a number of indications and novel targets for which its ability to integrate scientific insights around neurological dysfunction and the biology of misfolded proteins can be leveraged. Prothena’s pipeline includes both wholly-owned and partnered programs being developed for the potential treatment of diseases including ATTR amyloidosis with cardiomyopathy, Alzheimer’s disease, Parkinson’s disease and a number of other neurodegenerative diseases. For more information, please visit the Company’s website at www.prothena.com and follow the Company on X (formerly Twitter) @ProthenaCorp.